Hi does anyone know why I can't select 5 th and 6 th gear in my st170?

Can you be a bit more specific?

if its just 5th and 6th all other gears are ok then possibly the syncro it would be best to have it checked out

Is the gearbox cable operated or a mechanical linkage ? Could be the cable has broke or come adrift at one end.

if it was the cable you wouldnt get any gears does it crunch in any gears or 5th to 6th or is it silent but just wont go

[quote name='Damianst666' timestamp='1349364992' post='209633']
Hi does anyone know why I can't select 5 th and 6 th gear in my st170?
[/quote]

It goes in every other gear with out any noises. And the cables are fine.

sounds like the syncromesh ide have it checked out it may happen to other gears

Has the linkage been inspected? It could be that you have lost motion due to wear or it might just need adjusting.

How do I check that?

I had a good look at the cables today. The cables look fine however one of the plastic joints that have a spring is broke and the spring isn't doing anything could this be the course?